Automatic throw-out mechanism for gear cutting machines



April 25, 1933. FHN$EN LQQSASG AUTOMATIC THROW-OUT MECHANISM FOR GEARCUTTING MACHINES Filed March 28, 1930 4 Sheets-Sheet- 1 INVENTOR %&ATTORNEY April 25, 3933. E, FINSEN 1,905,456

AUTOMATIC THROW-OUT MECHANISM FDR GEAR CUTTING MACHINES Filed March 28,1950 v 4 Sheets-Sheet 2 INVENTOR gyz/mdflmsezz April 25, 1933. E N N1,905,456

AUTOMATIC THROW-OUT MECHANISM FOR GEAR CUTTING MACHINES Filed March 28,1956 4 Sheets-Sheet 3 WI mmmglgr INVENTQR @Uzrzd macaw h's ATTORNEY AApril 25, 1933. E. FINSEN 1,905,456

AUTOMATIC THROW-OUT MECHANISM FOR GEAR CUTTING MACHINES Filed March 28,1930 4 Sheets-Sheet 4 INVENTQR lf azrzd firasem he ATTO'RNEW PatentedApr. 25, 19 33 EYVIND FIN'SEN, OF ROCHESTER, NEVJ YORK, ASSIGNOR T 0GLEASON WORKS, OF

ROCHESTER, NEW YORK, ACORPORATION OF NEW YORK AUTOMATIC THRON-OUTMECHANISM' FOR GEAR CUTTING MACHINES Application filed March 28, 1930;

T he present invention. relates to machine tools and particularlyto-machines for cutting operable automatically after the work has beencompleted to separate the work from the tool mechanism a. sufficientdistance to permit removal of the completed work-piece and chucking of anew blank.

A further purpose of the invention. is to provide a mechanism of thenature described which can be readily applied to existing machines.

A still further object of this invention is to provide mechanism of thenature described whereby the operation of the tool or tools will bestopped automatically before the relative separation takes place andwhereby the starting of the tool mechanism into operation again isprevented until the operative relation has been restored so as toobviate any possibility that an operator suifer injury throughattempting to remove thecompleted work-piece or chuck a new blank whilethe tools are in motion.

Other objects of this invention will be apparent hereinafter from thedescription and from the recital of the appended claims.

In the drawings:

Figure 1 is a side elevation, with parts broken away, Sl10\ ing atypical spiral bevel gear generator and showing how the mechanism ofthis invention may be applied to such a machine;

Figure 2 is a fragmentary View on an enlarged scale, showing parts ofthe machine.

illustrated in Figure I and showing in section, the mechanism of thisinvention;

Figure 3 is a section on the line 33 of. Figure 2;

Figure 4 is a fragmentary sectional view of the automatic stop mechanismof the machine, taken on the line 4-4 of Figure 2 showing, also, insection, the limit-switch and the dash-pot device controlling the'speedof movement of the switch-bar.

Figure 5 is a fragmentary perspective view of the feed cam of themachine and associated parts;

Figure 6 is a diagrammatic view illustratchine.

the slide 11 on which the tool mechanism.

is mounted. In the machine shown, the tool;

Serial' No. 439,646.

ing the principle of operation of the mechanism. of this invention andshowing one method of wiring a machine to secure the desired results;and

Figure 7 is adetail view showing the means. for actuating the automaticstop mechanism.

The machine shown in the drawings is a machine of the general typeillustrated in the patent to James E. Gleason. et at, No..

1,722,464, issuediJuly 30, 1929 but the invention is, of course, notlimitedzinitsapplication to any particular type of machine...

lOdesignatesthe base or frame of the ma- 611 this base or frame 10 ismounted is a facemill cutter, as indicated at T. The base or frame 10carries at one endanupright 12 which serves as a support for theoscillating. cradle upon which the work head or carrier isadj ustablymounted. The gear blank Gr to be cut is secured. to the work spindle.

which is journaled in the work head.

The various parts referred. to are notillustrated specifically in thedrawings of the present application because they form no part of thepresent invention. 7

The slidell has a reciprocating movement during the operation of themachine to move the tool. mechanism alternately toward and from the workto cut tooth slots in the work during the forward movement and permit indeXing of they work when the tool is withdrawn. This reciprocatingmovement isof limitedlength, just enough to alternately feed the toolinto full depth. and clear the workfor the indexing. Then the gear iscompleted,.itis necessary to move the. tool: away fromthe work a greaterdistance-than. it is moved on the reciprocating motion. just describedin order to allow the completed gear to be taken 01% the machine and anew blank chucked.

The mechanism of this invention is provided to eifect this lastnamedmovement auto-' 'work have been completed. In the preferred form ofthis invention, the automatic stop mechanism of the machine is used toactuate the mechanism of the present invention. l/Vhen the stop operatesto stop the operating parts of the machine, such as, the tool mechanismand the parts producing the generating, feed and indexing motions, itimmediately thereafter causes the mechanism of this invention to beenergized to Withdraw the tool slide 11 from operative position toloading position. taken oflf of the work spindle and a new blank chuckedthereon.

Journaled in the base 10 of the machine is a shaft 86 and to this shaftare secured the cam 80 which controls the generating roll of the machineand the cam 110 which controls the reciprocating motion of alternatefeed and withdrawal imparted to the tool while in operative relationwith the blank.

The cam 80 is operatively connected with the cradle on which the Workspindle is mounted by means of a lever 82 and connecting rod 81, asdescribed in the patent above mentioned, but this mechanism forms nopart of the present invention and will not be referred to further here.

The cam 110 operates the slide 11 through a roller 111 which is mountedon a slide 112 (Figure 5) that is adjustable in a slot formed in theslide 11. The slide 112 is provided with a transverse slot 114 on itsupper face and the square port-ion 115 of the arm 116 engages in thisslot 114. The arm 116 is connected by means of a screw 117 with theslide 11. The

adjustable connection of the roller 111 with the slide 11 permits of avery fine adjustment of the slide 11 to set the tool T to proper depthand take up wear. It will be seen, however, that as the shaft 86 rotatesthe slide 11 'will be moved back and forth by reason of the engagementof the roller 111 with the trackway of the cam 110. On the forwardmotion of the slide 11, the tool cuts a groove in the blank and on thereturn motion the blank is indexed. The contour of the slot of the cam110'is such, however, as to limit the forward and return motion of theslide 11 to the amount required to cut teeth of the desired depth andjust clear the blank for indexing thereby reducing the operating time ofthe machine to a minimum.

The return stroke of the slide 11 does not carry the tool far enoughaway from the blank to permit taking the blank off of the work spindlefor chucking a new blank. It is necessary, therefore, to move the toolslide further away from the work head than is possible with the motionproduced by the cam 110. Heretofore, this has been done by hand.Journaled in the slide 11 is a stud shaft which carries the pinion 166that meshes with a rack 167 that is secured to the frame of the machine.Heretofore, the operator ran the slide 11 back to loading position andreturned it The completed gear can then be to operating position againafter the new blank had been chucked by rotating the shaft on which thepinion 166 was fixed. This was a slow and laborious operationparticularly since it has to be done many times in a day and to speed-upthe old process and relieve the operator of the burden of running theslide back and forth by hand the mechanism of the present invention hasbeen devised. This 'mechanism operates automatically to move the slide11 to loading position when the gear blank has been completed and can beactuated by simply pushing an electric push-button to return the slideto operative position. If desired the hand operated mechanism may belefton the machine to permit the tools being run back at any time ifoccasion should arise for such action before the gear is completed.

Secured to the framelO of the machine at one side thereof is a casting20 which houses the automatic throw-out mechanism of this invention.

The casting 20 is bored at 21 to receive the sleeve 22 in which thevalve 23 slides. Ducts 24 and 25 are drilled into the bore 21 atopposite ends thereof.

The casing 20 is bored above the bore 21 to provide a chamber 27. Theends of this chamber 27 are closed by the cap-pieces 28 and 29 to form acylinder in which the piston 30 reciprocates.

The ducts 24 and 25' communicate with opposite ends of the chamber 27 toconvey the pressure fluid alternately to opposite ends of the piston 30as controlled by the position of the valve 23.

The piston 30 includes the central disc 31, the leather cup-washers 32and 33 and the discs 34 and 35 which serve, respectively, to secure thwashers 32 and 33 to the central disc 31. The piston 30 is secured to apiston rod 37, intermediate the ends of said piston rod, by means of thelock-washers 38 and the nuts 39.

The piston rod 37 is of suiiicient length to project through and beyondthe end walls 28 and 29 of the cylinder in either limit position ofmovement of the piston. The end walls 28 and 29 of the cylinder aresuitably packed, as indicated at 42 and 43, respective ly, to preventleakage of the pressure fluid along the piston rod.

Secured to the slide 11 at one side thereof is a plate 45. 46 designatesa bracket which is adjustably secured to the plate 45 by means of bolts47 which pass through elongated slots 48 formed in the bracket 46 andthread into the plate 45.

Cast integral with the plate 46 are two downwardly projecting arms 49and 50.

When the piston 30 moves in the chamber 27, the piston rod 37 engagesone or other of the arms 49 or 50 to move the slide 11 either outwardlyto loading position or inwardly to operative position depending upon thediat i rection of movement of the piston. There is a slot 168 (Figure 5)formed in one side wall of the cam 110 so that the roller 111 can passfreely intoand out of engagement with' the cam 110 during the movementsof the slide 11 just described.

The casting is hollowed out to form a reservoir. The hydraulicmotive-fluid is pumped into this reservoir from a sump in the base ofthe machine by any suitable type of pump. The intention is to use forthis purpose the lubricating oil pump provided on the machine. Themotive-fluid enters the reservoir in the casting 20 through the pipe Itflows from the reservoir through the openings 53 and 54 into a duct 55which communicates with the bore 21 and through a series of radiallyarranged openings 56 formed in the sleeve into the valve chamber 57.

' proper.

cate, respectively, with the valve chamber 57 at opposite ends thereofand lead into ducts 6: and 65, respectively, that convey the fluidoutside of the casting 20 whence it drops back into the sump.

The valve stem 23 is formed intermediate its ends with shoulders 5'6 and67 which fit closely the bore of the sleeve 22.

In the position of the parts shown in Figure 2, the valve 23 is at onelimit of its movement in the valve chamber 57. The pressure fluid flowsfrom the reservoir inthe casting 20 through the openings 53 and 5% intothe duct 55, thence through the openings 56 into the valve chamber 57,whence the fluid flows through the openings 58 into the duct 60 andthrough the duct 2% into the chamber 27 forcing the piston 30 to theright from the position shown in Figure 2. The fluid is simultaneouslyexhausted from the right hand end of the piston 30 through the ducts and61,

the openings 59, the port 63 and the duct 65.

As the piston moves to the right, the piston rod 37 engages the arm ofthe bracket a6 and causes the slide 11 to be returned to operativeposition. TV hen it is desired to withdraw the slide 11 from operativeposition to loading position, the valve 23 is reversed through meanshereinafter to be described and the pressure-fluid then flows from thereservoir through the openings 53 and 54, the duct 55, the openings 56,the openings 59. the ducts 61 and 25, into the chamber 27, moving thepiston 30, piston rod 37 and slide 11 to the left to the position shownin Figure 2. In this movement, the fluid is exhausted from the left handend of the piston 30 through the ducts 24: and 60, the openings 58, theport 62 and the duct 6% whence it returns to the sump.

Solenoids and 71 arranged at opposite ends of the valve chambererteriorly thereof are employed to shift the valve 23. The valve 23 isshifted to the position shown in Figure 2 by energizing the solenoid 70.To

reverse the direction of movement of the pie-- ton 30, the othersolenoid 71 is energized. The solenoid 70 is energized from a pushbutton 7 2 secured to the machine at any convenient location (Figures 1and 6), while the solenoid 71 is energized in the operation of theautomatic stopping mechanism of the machine as will now be described.

This automatic stopping mechanism may be of any suitable type, such asis ordinarily employed on machines of the character described. T he stopshown in the drawings is that covered by U. S. patent to Maxwell H.Hill, No. 1,577,121, of March 16, 1926' and reference may be had to thatpatent for more detailed description of the o aeration thereof.

designates a limit-switch which is socured to the housing 91 of theautomatic stopf When the machine is in operation, the contact bar 92 ofthe limit-switch bridges the terminals 93 (Figures 4 and 6) to maintaina closed circuit between the line and the cutter and main drive motorsso that the machine will operate. on the lower arm of a bell-crank 94-which is pivotally connected at its upper end at 95 to an arm 96. Thearm 96 is bifurcated at its outer end and between the furcations thereofis pivotally mounted a bloclr 97. The arm 96 is constantly urged intohorizontal position by means of a coil spring 98 which is interposedbetween the inner end of the arm 96 and the wall of the limit-switchhousing. The spring 98 serves to insure the contact between the bar 92and the terminal 93 and restores this contact after it has been broken.

In the operation of the machine, the slide 11 is moved alternatelyinward to out and outward to permit indexing by the cam and roller 111,as has been described, and with each outward movement, the automaticstop mechanism is ratcheted forward'a tooth or teeth. The stop mechanismmay be advanced by any suitable means. For instance, as shown in Figure7 of the drawings, a cam 212 may be secured to one face of the feed cam110 so that on each revolution of the feed cam, the plunger 213 of theautomatic stop mechanism 91 is reciprocated to ad-' Vance the tripmechanism of the stop. The stop is adjusted for the number of teeth tobe cut in the blank and as the feed cam makes a complete revolutionduring the cutting of each tooth space and the indexing of the blankthereafter, when the last tooth has been cut in the blank the stop willbe tripped.

The contact-bar 92 is carried The trip-lever 99 of the stop will engagethe block 97 rock this block about its pivot 100 against the resistanceoi? the leaf-spring 101, and the trip roller 102 will engage under the 5block 97. The trip-lever will then immediately return to upper positionunder actua-,

tion of a spring in the automatic stop mechanism. In its upward movementthe roller 102 of the trip-lever will engage the block 97 which is nowheld against movement about its pivot 100 by engagement of the fiat rearsurface of the block with a corresponding surface on the arm. The arm 96is thus swung upwardly against the resistance of the spring 98 and thecontact between the bar 92 and the terminal 93 is broken. This stops thecutter motor and the main drive motor. This action is so timed that thecam .110, which is driven from the main drive motor,

stops with the roller 111 registering with the slot 168 in the side wallof the cam.

As the bar 92 breaks contact with the terminals 93, it makes contact onits opposite face with a pair of spring-pressed pin terminals 104 whichare electrically connected with the electro-magnet 71. The solenoid 71is thus energized and the valve 23 shifted to the right from theposition shown in Figure 2 to cause the slide 11 to be moved outwardly mto loading position as already describet lVhen the lever 99 has movedupwardly far enough it clears the block 97. The spring 98 then acts torestore the parts to normal position breaking contact between the bar 92and --the terminal pins 104 deenergizing the electro-magnet 71.

The valve 23 has to be moved some distance by the electro-magnet'? 1 toreverse the direction of application of fluid pressure to the LO-piston30 and, consequently, the electro-magnet 71 must be energized for a timelong enough to efiect this movement. To allow the solenoid 71 to beenergized long enough to effect the complete movement of the valve,

:51. dash-pot 122 is secured to the limit-switch housing 90. Thisclash-pot is so connected with the bell-crank 94 that while a quickmovement of the bell-crank 94 is permitted when contact at 93 is brokenand contact at 104 made, despite the action of the spring 98, the bar 92remains in contact with the pins 104 for a sufiiciently long time topermit the electro-magnet 71 to perform fully its function.

i7 123 designates the plunger of the dash-pot. To this plunger issecured a cup 124 which closely engages all around its periphery theinterior of the thimble 125. This thimble threads into the bracket 126that is secured th the housing of the limitswitch. The

thimb-le 124 contains oil or some other suit-' able fluid. The cup 124is secured to the plunger 123 by means of nut 126 and a washer 127. Thebottom of the cup 124 is perfo- 128 and 128. 129 indicates a washer thatis movable relative to the plunger 123. The inside wall of this washer129 is spaced from the periphery of the plunger 123 so that the washermay cover the holes 128 but will not cover the holes 128. The holes 128are larger in diameter than the holes 128.

When the plunger 123 moves downwardly in the thimble 125, the pressureof the oil in the thimble lifts the disc 129 off of the bottom of thecup 124 and the oil fiows freely tl rough the openings 128 as well asthe openings 128 but when the plunger 123 moves upwardly the pressure ofthe oil seats the disc 129 firmly on the bottom of the cup shutting theopenings 128 and the plunger and cup can only move upwardly slowly atthe rate permitted by the flow of oil through the holes 128'.

The plunger 123 is headed, as indicated at 30. 131 indicates an armwhich is furcated i one end to engage the plunger 123 beneath the head130 and at the reduced portion of its diameter. This arm 131 is pivotedin the bracket 126 at 132 and is pivotally connected at its other end,as indicated at 133 to the bellcrank 94.

A cover, designated at 135, is secured to the bracket 126 to prevententrance of foreign matter into the chamber of the dash-pot.

The operation of the throw-out mechanism can now be described.

160, 161 and 162 designate the main power lines conducting electricityto the machine. These are connected to the terminals of a magneticstarter 164 which may be of any usual or suitable construction. Thereare many different kinds of magnetic starters manufactured tor the tradeby concerns engaged in the production of electrical equipment.

In the machine shown in the drawings, a separate motor is employed fordriving the cutter from that used for driving the rest of the machine.In the drawings these two motors 165 and 166, respectively, areillustrated as three-phase motors. The main motor 166 is connected bylines 167, 168 and 169 with terminals of the magnetic starter 164 whilethe cutter drive motor 165 is connected to terminals or" the magneticstarter by lines 170 and 171 and through the line 172 and the line 169.

Assuming the parts to be in the position shown in Figures 2 and 6 withthe tool slide 11 in loading position and the parts of cutting machineand of the throw-out mechanism at rest, if it be desired to return theslide 11 to operative position, the operator pushes in the push-button72. This push-button may be located at any convenient point on themachine. Vhen it is closed, the circuit extends from the main line 160through the line 174 or the starter, the line 175, the termi- GSi-ratedto provide two concentric series of holesnals of the push-button 72 theline 176, the

electr c-magnet 70, the line 177, and the line 17 8 to the main line162.

The solenoid 70 being thus energized moves the valve 23 to the positionshown in Figures 2 and 6. The motive fiuidtlows from the reservoir inthe casting 20 through the openings 53 and 5 1, the duct 55, theopenings 56,

the openings 58. the ducts-60 and 24- to the left hand end of the piston30, shifting this piston and the piston rod 37 to the right from theposition in Figures 2 and 6. As the piston rod moves to the right itengages the arm 50, carrying the bracket 16 on the slide 11 to the rightand returning the slide to 0perative position with the roller 111re-engaged in the trackway of the cam 110.

The moment that the cam roller 'reenters the cam trackway the lug 1&0 onthe bracket 16 engages the roller 141 of a limit-switch 1 12, depressingthis roller and the switch arm to which it is attached against theresistance of the coil-spring 1 13. The switch 112 is a normally openswitch, so that this action of the lug 1 10 closes the switch andcompletes the circuit through the terminals 98 and the bar 92 of thelimit-switch 90, to the m .etic starter. This closing of the circuitmight be employed to start the cutter and main-drive motors but as it issometimes "has .hle to stop these motors before the gear has beencompleted, separate start and stop buttons 1 and 14.- respectively, arepik and stopping of these motors. Howeven'it i to be noted that thesemotors cannot bestarted until the switch 142 has been closed by theengagement of the lug 140 with the r lhr 14-1 thereof.

n the piston 30 reaches the limit of its cut to the right it simplybottoms in the cylinder.

The cutter and main-drive motors are now stited by pressing the startbutton 145. l hen the push-button is closed. a circuit is 5 osed the lin1 5, the line 180, the terminals of the start button 145, the line 182,the line 188. the line 184'. the coil 185 of an electromagnet in themagnetic starter, and the line 186 of the starter to the main line 162.This energizes the electro magnet 185 and pulls in the tour switch arms188. 189, 190 and 191 caus ng each of these to close a line. The p I otthe switches 188, 189, 190 and 191 los tie circuit to the cutter andfeed motors, the lines 169 and 172 being then connected to the main line162 through the switch 191; the lines 168 and 170 being cond to the mainline 161 through the h arm 196: and the lines 16'? and 171 he connectedto the main line 160through the switch arm 188 and the line 198.

The hutton 115 is. a normally open button and when the operator releasesit, it flies )Ptil. The circuit is maintained, however to :fiblYprovided to control. the starting tron: the line 160 through the line 171,

the two drive motors through the switch arms 188, 190 and 191 by theaction of the electro-magnet 185. This electro-magnet remains energizedafter the machine has been started, despite the opening of the button145. for the circuit to itis maintained from the line 162 through. theline 186, the line 18 1, the line 183. the line 182, the line 194, thenormally closed stop button 116, the line 195,

the switch 142, the line 196, the terminals'93 and the bar 92, the line197, the line 198, the swit h arm 189. which is closed when theelectroqnagnet is first energized and remains closed until the circuitto the electromagnet is broken, and the line 199 back to the main line160.

The main motor having been started, the cam 110 will be rotated tooperate the slide 11, moving it alternately inward to feed the rotatingcutter into the blank to cut a tooth space in the blank and withdrawingitto permit indexing the blank after each slot has been completed. Oneach withdrawing motion, the automatic stop mechanism will be advanced.The alternate feeding and withdrawal for indexing will continue untilallotthe teeth have been cut in the blank. On the last withdrawingmotion, the automatic stop will be tripped, the lever 94 of the stoppassing down beneath the block 97 rocking this'block aside and returningto upper position, engaging the block 97 and rocking the arm 96 upwardlyagainst the resistance of the spring 98. This movement breaks thecontact between the bar 92 and the terminals 93. This breaks the circuitto the electromagnet 185, releasing the switch arms 188, 18 190 and 191,and thus causing the circuit to the cutter and main drive motors to bebroken stopping the operative functions of the machine. Immediatelyafter breaking contact 93, the bar 92 makes contact with the pins194t.This closes a circuit to the so enoid 71 from the main line 160 throughthe line 1741., the line the line 200, and the pins 104. and the bar 92,the line 201, the coil of the electro-magnet 71, the line 202, the line1.77 and the line 178 to the main line 162. The solenoid 71 is thusenergized to draw he valve 23 to the right from the position shown in Aigures 2 and 6. The springs 98 tend to move the arm 96 back tohorizontal position but contact between the bar 92 and thespring-pressed pins 104 is maintained long enough to move the valve 23completely to the right by the action of the dashpot secured to thelimit-switch 90. This dash-pot lets the arm 96 swing upwardly quicklyunder action of the lever 91 to break the circuit to the cutter and maindrive motors but allows the arm to return to horizontal position onlyvery slowly.

W th the valve 23 drawn to the right, the motive "fluid passes from theduct 55 and the openings 56, out of the opening 59 into the ducts 61 and25 to the right hand end of the piston 30 moving the piston and pistonrod back to the left to the position shown in Figure 2. This movementcontinues until the piston 30 has bottomed in the cylinder as shown inFigure 2 and the slide 11 will then have been withdrawn to loadingposition. The operator can then readily remove the completed gear andchuck a new blank.

The spring 98 remakes the contact between the bar 92 and the terminals93 but as the circuit to the terminals 98 is open, the cutter slide 11remains in withdrawn position. In order to again return the slide 11 tooperative position, it is only necessary for the operator to againdepress button 72.

It is to be noted that the distance between the opposed faces of thearms 49 and 50 is greater than the l ngth of the piston rod 3?. This isto permit the alternate movement of the slide 11 for feeding andwithdrawal, when in operative position, to take place without the valve23 being shifted.

As the cutter and main drive motors are stopped by the action of theautomatic stop and as the circuit to these motors remains broken duringthe functioniugof the piston 30, and as the circuit can not e remadeuntil, in the movement of the slide 11 to the right, the lug 14:0engages and depresses the limitswitch 142, it will be seen that alldanger of injury to an operator from coming into contact with the cutterduring the chucking operation is entirely eliminated. This is asafetyfeature of the machine worthy of note.

A head of air is maintained in the chamber formed in the casting 20 sothat the motive fluid is immediately responsive to any movement of thevalve 23. Air-leakage is not entirely avoidable, so means has beenprovided for replenishing the air in the chamber 20 so as to maintainthe necessary pressure in the system. 150 designates a fourway valve.This screws into an opening in the casting 20 to communicate with thereservoir. Normally, the valve is so positioned that fluid flowing intoit from the casting 20 will pass through the pipes 151 and 152 back intothe casting.

When the pressure in the piston falls too low, the valve is turn d bythe wrench 153 so that the oil flows out of the reservoir 20 through thepipe 15s back into the sump and so that the other arm of the valve isopened to the air. lVhen the oil has been exhauster from the reservoirthe reservoir fills with air. When the valve is shut again, the oilpumped into the reservoir from the pipe 52 compresses the air in thereservoir, restoring the pressure in the system.

The invention has been described as applied to a particular machine, butit will be understood that it is obviously capable of various furtherapplications. It is to be understood, also, that it is not limited tothe embodiment shown. The invention is capable of various furthermodifications and uses without departing from the scope of the in- Hscope of the invention or the limits of the ap- H pended claims.

Having'thus described my invention, what I claim is:

1. In a machine for cutting gears, tool mechanism and a work support,means for moving one of said parts toward and away from the otherthrough a limited distance for alternate feeding and indexing, means forautomatically stopping the tool mechanism after a predetermined numberof operations have been performed, means operable automaticallythereafter for producing a relative movement of separation between thetool mechanism and the work support to permit removal of the completedgear and chucking of a new blank, means for actuating said last namedmeans to return the tool mechanism and the work support into operativerelation, and means operable when said return movement has beencompleted for rendering the tool mechanism operative.

2. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, means for moving said slidealternately in opposite 1' directions for alternate feeding and indexingmeans for automatically stopping the last named means and the toolmechanism when a predetermined number of operations have been performed,separate means for automatically withdrawing said slide from operativeposition when the predetermined number of operations have been performedto permit removal of the completed gear and chucking of anew blank, saidlast named movement acting to disengage the slide from operativerelation with the first named actuating means, means for actuating thelast means to return the slide to operative position, and means operablewhen the slide has returned into operative relation with the first namedmeans to render the tool mechanism and the first named means operative.

3. In a machine for cutting gears, tool mechanism and a work support,means for moving one of said parts alternately in opposite directions toproduce alternate movements of feed and withdrawal between the toolmechanism and the work, and means operable automatically after apredetermined number of feed movements for disengaging iib eona-5s saidmovable partfrom the-first'named means and for immediately thereafterautomatically moving said part to loading position.

4. In a machine for cutting gears, tool mechanism and a work support,means for moving one of saidparts alternately in opposite directions toproduce alternate move ments of feed and withdrawal bet-ween the toolmechanism and the work within a limited path, and separatefluid-pressure operated means operable automatically after apredetermined number of feed movements for moving the movable partbeyondsaid limited path to move said part to inoperative position.

5. In a macl ine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, means for moving the slidealternately in opposite directions through a limited distance foralternate feeding and indexing, fluid-pressure operated means comprisinga piston movable in a cylinder for moving said slide independently ofthe first named means, a valve controlling the direction of applicationof fluid-pressure to said piston, and means adapted to be operatedautomatically when a predetermined number of operations have beenperformed to move said valve to apply fluid-pressure to said piston soas to withdraw the slide from operative position for removal of tcompleted gear and chucking a new blank.

6. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, means for moving the slidealternately in opposite directions through a limited distance foralternate feeding and indexing, separate fluid-pressure operated meanscomprising apiston movable in a cylinder for moving said slide fromoperative to inoperative position, a valve controlling the direct-ion ofapplication of fluid-pressure to said piston, means for automaticallystopping the tool mechanism when a predetermined number ofopera'tionshave been performed and for immediately thereafter moving said valve toapply fluid.-

.r pressure to the withdrawal side of said pis- ";on to withdrawthe-slide from operative position to permit removal of the completedgear and chucking of a new blank.

7. In a machine for cutting gears, tool mechanism and a work support, aslide on zvhich one of said parts is mounted, fluidpressure operatedmeans comprising piston movable in a cylinder for moving said slide, avalve cont olling the direction of applica tion of fluid-pressure tosaid piston, meai Ior automatically stopping the tool mechanism whenpredetermined number of opera tions have been performed and forimmediately thereafter moving said valve to apply fluid-pressure to thewithdrawal side of said piston to withdraw the slide from operativeposition to permit removal of the completed gear and chucking of a newblank, means for reversing said valve to cause the slide to return intooperative position, and means operable on return movement of said slideto renfor moving said slide alternately in opposite directions toproduce alternate movements of feed and withdrawal between the toolmechanism and the work, separate fluid-pressure operated means formoving said slide from operative to inoperative position, a valvecontrolling said fluid-pressure operated means, an electro-magnetadapted to be energized to move said valve to cause the fluid-pressureoperated means to withdraw the slide from operative position, and meansadapted to be operated after a predetermined number of operations havebeen performed to energize aid electro-magnet.

9. In amachine of the class described, tool mechanism and a worksupport, a slide on which one of said parts is mounted, fluidpressureoperated means for moving the slide in opposite directions, a valvecontrolling said fluid pressure operated means, a pair ofelectro-magn'ets controlling the direction of movement of said valve tocontrol the direction of application of fluid-pressure to saidfluid-pressure operated means, means operable when the desired number ofoperations have been completed on the work to stop the tool mechanismand immediately thereafter energize oneof said electroanagnets to causethe slide to be withdrawn from operative position to permit removalof'the completed Work-piece and chucking of a new blank, means operableto energize the other electromagnet to cause the slide to be returned tooperative position, and means operable on said return movement to renderthe tool mechanism operative.

10.1n a machine of the class described, tool mechanism and a Worksupport, means comprising a cam and a roller engageable therewith formoving one of said parts back and forth through a limited distance toeffect the required number of operations on the work, said cam having aslot in one wall of its trackway through which the roller may be movedto disengage the roller from the traokway, means adapted to be operatedautomatically after a predetermined number of operations have beenperformed to stop said cam with the roller in line with said slot, andmeans operable automatically immediately thereafter to move said movablepart in the same direction as for its limited movement to disengage theroller from the cam and move said part to inoperative position to permitremoval of the completed work and chucking of a new blank.

11. In a machine of the class described, tool mechanism and a worksupport, means comprising a cam and a roller engageable therewith formoving one of said parts back and forth through a limited distance toeffect the required operations on the work, said cam having a slot inone wall of its trackway through which the roller may be moved todisengage the roller from the traekway, means adapted to be operatedautomatically after a predetermined number of operations have beenperformed to stop said tool mechanism and stop said cam with the rollerin line with said slot, means for thereafter automatically moving saidmovable part to disengage tie roller from the cam and move said part toinoperative position to permit removal of the completed work andchucking of a new blank, means for reversing the direction of operationof said last named means to cause the same to return the movable part tooperative position and cause the roller to be reengaged with said cam,and means operable for rendering said tool mechanism and said camoperative when the parts have been returned to operative position.

12. In a machine of the class described, tool mechanism and a worksupport, a slide on which one of said parts is mounted, means comprisinga cam and a roller engageable therewith for moving one of said partsback v and forth to effect the working cycle, said cam having a slot inone wall of its traekway through which the roller may be moved todisengage the roller from the traekway,

fluid-pressure operated means operable to move said movable part toinoperative position to permit removal of the completed work andchucking of a new blank, and means oparable when the desired number ofoperations have been performed for automatically stopping said cam withsaid roller in register with said slot and for immediately thereafteractuating said fluid-pressure operated means.

13. In a machine of the class described, tool mechanism and a worksupport, a slide on which one of said parts is mounted, means comprisinga cam and a roller engageable therewith for moving one of said partsback and forth to effect the working cycle, said cam having a slot inone wall of its traekway through which the roller may be moved todisengage the roller from the traekway, fluidpressure operated meansoperable to move said movable part to inoperative position to permitremoval of the completed work and chucking of a new blank, and meansoperable when the desired number of operations have been performed forautomatically stopping said cam with said roller in register with saidslot and for immediately thereafter actuating said fiuid-pressureoperated means, means operable to cause return of said part to operativeposition, and means operable when the part has been returned tooperative position and the roller is reengaged with the cam to restartthe cam to resume the working cycle.

14. In a machine of the class described, tool mechanism and a worksupport, a slide on which one of said parts is mounted, means comprisinga cam and a roller engageable therewith for moving one of said partsback and forth to effect the working cycle, said cam having a slot inone of its walls through which the roller may be moved to disengage theroller from the traekway, a piston and cylinder, a piston rod projectingthrough said cylinder at both ends thereof and having the piston securedthereto at a point intermediate said ends, a bracket adjustably securedto said slide having a pair of arms projecting therefrom, the length ofsaid piston rod being less than the distance between opposed faces ofsaid arms whereby a limited relative movement is permitted between thepiston rod and said bracket, and means operable when a predeterminednumber of operations have been performed to stop said cam with theroller aligned with said slot and thereafter immediately causeapplication of fluid-pressure to one side of said piston to cause saidslide to be moved to inoperative position for removal of the completedwork and chucking of a new blank.

15. In a machine of the class described, tool mechanism and a worksupport, a slide on which one of said parts is mounted, means comprisinga cam and a roller engageable therewith for moving one of said partsback and forth to effect the working cycle, said cam having a slot inone of its walls through which the roller may be moved to disengage theroller from the cam traekway, a piston and cylinder, a piston rodprojecting from said cylinder at both ends thereof and having the pistonsecured thereto at a-point intermediate said ends, a bracket adj ustablysecured to said slide having a pair of arms projecting therefrom withwhich the ends of said piston are adapted to engage to move the slide inopposite directions, the length of said piston rod being less than thedistance between opposed faces of said arms whereby a limited movementis permitted between the piston rod and bracket, a valve controlling thedirection of application of fluid-pressure to said piston,electro-magnets adapted to be energized to move said valve in oppositedirections, means operable when a predetermined number of operationshave been performed to stop said cam with the roller aligned with saidslot and thereafter immediately cause one of said electro-magnets to beenergized to cause said slide to be moved to inoperative position topermit removal of the completed gear and chucking of a new blank, meansfor energizing the other electro-magnet to cause said slide to bereturned to operative position, and means operable when the roller hasbeen re-engaged with the cam to restart said cam to resume the workingcycle.

16. In a machine for cutting gears, tool mechanism and a Work support, aslide on which one of said-parts is mounted, means comprising a cam anda roller engageable therewith for reciprocating said slide through alimited working path to produce alt-ernately relative feed andwithdrawal move ments between the tool mechanism and the work support,means for actuating the tool mechanism, means for driving said cam,means operable, after a predetermined number of movementsof the slide,to stop the tool mechanism and the cam, and meansoperable automaticallyimmediately thereafter to withdraw the slide from engagement with thecam to move the slide from its working path to loading position.

17. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, means comprising a cam anda roller engageable therewith for reciprocating said slide through alimited working path to produce alternately relative feed and withdrawalmovements between the tool mechanism and the work support, and separatefluid-pressure operated means operable automatically, after apredetermined number of reciproc-ations of said slide through itsworking path, to withdraw said slide from its working path to loadingposition.

18. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, means for reciprocatingsaid slide through a limited working path, electrically operated meansfor driving the tool mechanism, the circuit to said drive mechanismincluding a normally open switch, means on the slide adapted to closesaid switch, when the slide is in working position to render said tooldrive operative, and means for automatically moving the slide'to loadingposition, when a predetermined number of operations on the blank havebeen completed, thereby simultaneously breaking the circuit to the toolmechanism.

19. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, electrically operated meansfor driving the tool mecha nism, the circuit to said drive mechanismincluding a normally open switch, means for reciprocating said slidethrough a limited working path, means on said slide adapted to closesaid switch, when the slide is in working position to render said tooldrive operative, separate electrically controlled mechanism for movingsaid slide to loading position, and means operable automatically, aftera predetermined number of operations on the blank, to actuate said lastnamed electrically operated mechanism to move the slide to loadingposition, thereby simultaneously breaking the circuit to the toolmechanism.

20. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, means for reciprocatingsaid slide through a limited working path, and separate means operableto move the slide to and from loading position comprising a piston andcylinder, one of which is connected to the slide and the other to theframe of the machine, a valve for controlling the direction ofapplication of fluid pressure to the piston, an electro-magnet operableto shift the valve in one direction to apply fluid pressure to thewithdrawal side or" the piston, and means operable automatically, aftera predetermined number of working cycles, to energize said electromagnetto cause withdrawal of the slide to loading position.

21. In a machine for cutting gears, a tool mechanism and a work support,a slide on which one of said parts is mounted, means for reciprocatingsaid slide through a limited working path, means, which are normallyinoperative, for driving the tool mechanism, means on the slide operablewhen the slide is in working position to render the drive to the toolmechanism operative, and separate means operable to move the slide toloading position comprising a piston and cylinder, one of which'isconnected to the slide and the other to the frame of the machine, avalve for controlling the direction of application of fluid pressure tothe piston, an electro-magnet operable to shift the valve in onedirection to apply fiuid pressure to the withdrawal side of the piston,and means operable automatically, after a predetermined number ofworking cycles, to energize said electromagnet to cause withdrawal ofthe slide to loading position.

22. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, m'eans for reciprocatingsaid slide through a limited working path, means for driving the toolmechanism, means on the slide operable, when the slide is in workingposition, to render the drive to the tool mechanism operative,- meansfor automatically moving the slide to loading position, when apredetermined number of operations on the blank have been completed,thereby simultaneously rendering the drive to the tool mechanisminoperative.

23. In a machine for cutting gears, tool mechanism and a work support, aslide on which one of said parts is mounted, a cam and a roller forreciprocating said slide through a limited working path, said cam:

having a slot in one side thereof, separate means operable to move theslide to and from its leading position comprising a piston and a,

i for reciprocating said slide through a limited working path, andseparate means operable to move the slide to and from loading positioncomprising a piston and cylinder, one of which is connected to the slideand the other to the frame of the machine, a valve for controlling thedirection of application of fluid pressure to the piston, a pair ofelectro-magnets energizable for shifting the valve in oppositedirections to cause movement of the slide respectively to and fromloading position, and means operable automatically, after apredetermined number of working cycles, to energize the electro-magnetwhich controls the movement of the slide to loading position.

25. In a gear cutting machine, a tool mechanism and a work support, aslide on which one of said parts is mounted, means for reciprocatingsaid slide through a limited working path, means for driving the toolmechanism, means on the slide operable, when the slide is'in workingposition, to render the tool mechanism operative, and means operable tomove the slide to and from working position comprising apiston andcylinder,

one of which is connected to the slide and the other to the frame of themachine, a valve for controlling the direction of application of fluidpressure to the piston, a pair of electromagnets energizable forshifting the valve in opposite directions to cause movement of theslide, respectively, to and from loading position, and means operableautomatically after a predetermined number of working cycles, toenergize the electro-magnet which controls the movement to loadingposition.

26. In a machine of the class described, a tool support, a work support,a tool mechanism mounted on the tool support, means for actuating thetool mechanism, a cam and a i V roller engageable therewith for movingone of said supports back and forth through a limited distance, andmeans adapted to be operated automatically, after a predetermined numberof such movements, to stop said tool actuating mechanism and withdrawthe roller from engagement with the cam and move said movable support toinoperative position to permit removal of the completed'work andchucking of a new blank, means operable to cause said last-named meansto return the movable support into 0perative position and bere-connected with said cam, and means operative when said support hasbeen returned to operative position for restarting thetool actuatingmechanism'and' saidca 27. In a machine of the class described, toolmechanismand a work support, means for imparting alternate movements offeed and Withdrawal to one of said parts to cause the same to be movedwithin a limited path, means for actuating the, 'tool mechanism, meansfor moving the movable part from said limited path to inoperativeposition, means operable automatically after a predetermined number ofmovements in the limited path to stop said tool actuatingmechanism'andrender the'last described means operative, and meanspreventing re-starting of the tool mechanism until the tool mechanismand work support have been restored to operative relation.

28. In a machine of the class described, a tool support, a work support,tool mechanism mounted on the tool support, means for actuating the toolmechanism, means for imparting alternate movements of feed andwithdrawal to one of said supports in a limited path, separate means formoving the movable support from the limited path to inoperativeposition, means operable automatically after a predetermined number offeed movements

